This work focused on the issue of postsecondary access and the successful preparation of high school students to meet the A-G Subject Requirements for admission to the State of California universities. A growing number of California students interested in attending the University of California and the California State University campuses face increased matriculation risks as education policies and state legislation, such as reduced postsecondary outreach services and decreases in pupil personnel support, prompt major changes to public school budgets and higher education opportunities. Now, more than ever, effective and efficient means of preparing all, not just some, eligible high school students for university matriculation are needed. Several studies have been conducted estimating the number of fully eligible California high school students and one study, in particular, concentrated on the specific factors that limit students with most of the admission requirements from becoming fully eligible. This current work expanded that latter study by striving to understand the dynamics of graduates who miss meeting the UC/CSU A-G Subject Requirements for admission by a margin of one to three semesters. Further, a cursory effort was made to examine the educational environment where the near-miss phenomenon occurred. The Central Valley is notorious for low rates of college prepared graduates to either the University of California or the California State University systems. Guided by a cluster analysis to increase the opportunity to generalize the results to other California secondary schools, three California high school campuses in the Central Valley were selected. Graduate transcripts from the sample high schools were analyzed regarding students' college preparedness--with a specific focus on the completion of the UC/CSU A-G Subject Requirements. This "within schools and across schools" transcript analysis provided a detailed description of each "near-miss" graduate and a summary of the nature and severity of the near-miss issue at each school site. These results were coupled with institutional characteristics, policies, and the role of institutional agents at the individual campuses. This analysis publicly initiates an investigation to capture the size and essence of the loss occurring at the margin with high school graduates only narrowly missing the opportunity for admission to California's public universities. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]